Typescript error on passing condition argument

[vholik]

Describe the bug

I'm using this guide to setup rbac in my application https://casl.js.org/v6/en/cookbook/roles-with-static-permissions.

Here is my final code:

import {
  createMongoAbility,
  ForcedSubject,
  CreateAbility,
  MongoAbility,
  AbilityBuilder
} from '@casl/ability'
import { MedusaError } from '@medusajs/framework/utils'
import { MemberDTO, MemberRole } from 'src/modules/seller/types'

export const actions = ['manage', 'read', 'create', 'update', 'delete'] as const
export const subjects = [
  'Invite',
  'Member',
  'Seller',
  'Product',
  'all'
] as const

type AppAbilities = [
  (typeof actions)[number],
  (
    | (typeof subjects)[number]
    | ForcedSubject<Exclude<(typeof subjects)[number], 'all'>>
  )
]

export type AppAbility = MongoAbility<AppAbilities>
export const createAppAbility = createMongoAbility as CreateAbility<AppAbility>

type DefinePermissions = (
  member: MemberDTO,
  builder: AbilityBuilder<AppAbility>
) => void

type Roles = MemberRole

const rolePermissions: Record<Roles, DefinePermissions> = {
  [MemberRole.OWNER]: (member, { can }) => {
    can('manage', 'all')
  },
  [MemberRole.ADMIN]: (member, { can }) => {
    can('manage', 'all')
  },
  [MemberRole.MODERATOR]: (member, { can }) => {
    can('read', 'Product')
    can('read', 'Invite')
    can('read', 'Seller')
    can('read', 'Member')
    can('update', 'Member', { id: member.id })
  }
}

export function defineAbilityFor(member: MemberDTO) {
  const builder = new AbilityBuilder(createAppAbility)

  if (typeof rolePermissions[member.role] === 'function') {
    rolePermissions[member.role](member, builder)
  } else {
    throw new MedusaError(
      MedusaError.Types.UNEXPECTED_STATE,
      `Trying to use unknown role "${member.role}"`
    )
  }

  return builder.build()
}

But I get this typescript error that I can not pass id in here

can('update', 'Member', { id: member.id })

Changing syntax to mongo query does not help.

Expected behavior
I should not get any typescript error

[stalniy]

could you please point me to the line where you tell casl the shape of Member subject type?

[vholik]

@stalniy are you refering to the fact that I should pass DTO types together with the subject strings?

export type Action = 'manage' | 'read' | 'create' | 'update' | 'delete'
export type Subject =
  | 'Invite'
  | 'Member'
  | 'Seller'
  | 'Product'
  | 'all'
  | MemberDTO
  | MemberInviteDTO
  | SellerDTO
  | ProductDTO

[stalniy]

Yes and DTO should be connected with subject type.

You can read about it here - https://casl.js.org/v6/en/advanced/typescript#infer-subject-types-from-interfaces-and-classes

The thing is that you need to wrap your DTOs with ForcedSubject<T> only if your DTOs do not know their type names (just simple POJOs)